Another cheap way i read in a magazine was to take a 5 gallon bucket with top, a peice of rebar or all thread and a 4 or 5 foot chain.
We call these "hog toys" work well but the 5 gal buckets are easily destroyed. We switched to the blue 33-44 (can't remember) barrels. Drill a hundred or so 1/2 inch and 9/16 inch holes all over it. Get the kind with plastic screw on lid and screw 3 screws in the threaded band. Put a hole big enough for your rope and put a good large knot in it in the bottom of the barrel. Fill with up to 2oo pounds corn and several packs of fruit punch kool-aid powder. Leave standing with a little sour corn on ground around it. You will know when they found it as they barrel will be on it's side. We used 30 feet of rope tied to a tree and the barrel would get rolled all over the available distance.